Solana : Error : failed to retrieve latest blockhash : TypeError : fetch failed in Anchor test
Error: Solana failed to fetch the latest block hash using Anchor test
The error message “TypeError: fetch failed in Anchor test” indicates that the Anchor testing library is unable to retrieve the latest block hash from the Solana network. This issue can occur for a variety of reasons, including changes to the RPC (Remote Procedure Call) interface or compatibility issues with the fetch method.
In this article, we will explore possible solutions to resolve the error and successfully fetch the latest block hashes on Solana using Anchor.
What is a Block Hash?
A block hash is a unique digital fingerprint of a block on the blockchain. It represents a specific transaction and is used to track the transaction history on the network.
RPC Interface Changes: Possible Cause
There have been changes to the latest RPC interfaces using the fetch method that may affect the way you access block hashes. Anchor uses a different API than some other testing libraries, such as Web3.py or solana-api. To resolve this issue, you can try the following steps.
- Update Anchor to the latest version
: Make sure your Anchor installation is up to date with the latest version.
- Check the RPC interface documentation: See the [Anchor API documentation] ( to make sure you understand how to access block hashes using the “fetch” method.
Compatibility issues: Possible cause
Another possible cause for this error is a compatibility issue between your testing library and Anchor. The fetch method may not work as expected due to a different implementation or API usage.
- Try an alternative RPC interface: If you are having issues with the fetch method, try using a different RPC interface that is compatible with the version of Anchor you are using.
- Check your testing library documentation: Refer to the documentation for your preferred testing library (e.g. Web3.py or solana-api) to see if there are any known compatibility issues.
Code example
You can use the following code snippet to get the latest block hash:
import anchor from 'anchor';
const connection = await anchor.connect();
console.log(connection.getLatestBlockhash());
Note that this requires the anchor library and it has been updated to work with Solana’s latest RPC interface.
Conclusion
The “TypeError: Fetch failed in anchor test” error can be resolved by updating Anchor to the latest version, checking the RPC interface documentation, or trying alternative RPC interfaces. Additionally, you may need to resolve compatibility issues between your testing library and Anchor.
By following these steps and experimenting with different approaches, you should be able to successfully obtain the latest block hashes on Solana using Anchor.